PCI Express emerged from the skirmishes over interconnect standards in the late 1990s. In 1998, IBM, Hewlett-Packard and Compaq formed a consortium to create PCI-X because of their collective frustration over the slow pace of PCI development. Months later, Intel came out with an interconnect standard called NGIO, or next-generation input-output, as a potential successor to PCI-X. The major server companies then developed Future I/O. Eventually, Future I/O and NGIO were merged into InfiniBand. Intel then developed 3GIO, or third-generation input/output, in 2001. Also known as Arapahoe, the technology was adopted by the PCI SIG in August 2001. In the end, the momentum to transform InfiniBand into a PCI replacement stalled, equipment makers adopted PCI-X, and PCI Express became the anointed successor. Advanced Micro Devices and some others, though, are adopting HyperTransport for similar functions. PCI Express will change the innards of desktops, according to Pete MacWilliams, an Intel fellow. It will start to replace the current PCI bus inside PCs, which connects the processor to peripherals such as printers, as well as the AGP bus, which connects the processor to the graphics chip. A variant of PCI Express will also eventually replace the "southbridge" in PC chipsets, a companion chip that connects the processor to the outside world. It will not, however, be used to replace the "northbridge," which connects the processor to main memory. The chipset consists of the northbridge and the southbridge. "It is going to be a really big deal," MacWilliams said. To show PCI Express' benefits, Intel has developed a concept PC called Powersville that uses a processor called Tejas. Intel will begin to deliver PCI Express chips in the second half of this year to manufacturers, and computers based on the Powersville design are expected next year. Intel also is delivering toolkits to software and hardware developers to ensure that future products will be PCI Express compatible. Texas Instruments and other companies are equally enthusiastic and will be releasing PCI Express components next year or late this year. Beyond the basics
While the PCI-SIG has signed off on the basic standard, more work is afoot. The group has finished a specification for add-in cards based on PCI Express, said Tony Pierce, PCI-SIG chairman and a Microsoft employee. This will be used to design plug-in cards for high-speed networks or IEEE 1394 "FireWire" connections. PCI Express researchers are working on a version that would allow signals to be transferred across a cable, making it possible to physically separate parts such as the processor and memory from network and storage subsystems. Networking companies will begin to adopt PCI Express as well. For example, AdvancedTCA, a standardised blueprint for building networking equipment, relies on the standard. So far, 28 companies have announced plans to introduce 70 AdvancedTCA products in 2003, according to Udayan Mukherjee, technology architect and ATCA initiative manager at Intel, which is also driving the TCA standard. But in the server market, competitor PCI-X looks likely to prevail in the nearer term. Currently, Dell, a close Intel ally, appears to be the strongest server backer of PCI Express, according to Insight64 analyst Nathan Brookwood. "Sun, IBM, and HP seem very committed to PCI-X. Dell's been lined up with Intel on PCI Express," he said. The trouble for server companies could come if they pick a technology, like InfiniBand, that doesn't develop according to plan. It's the kind of bet that must be made years in advance while next-generation products are in the design stage, and making the wrong choice means losing market share, Brookwood said. The current economic climate also reduces any urgency to switch. Back when 3GIO was first making its way into the industry, Intel said it would arrive in computers in 2003, but ServerWorks took a more cautious approach, predicting correctly that timetable was a year too fast. Intel is more active than ServerWorks in driving technology change, Illuminata analyst Gordon Haff said. "ServerWorks tends to take the attitude that once it's been proven that there's a market for a technology, (they'll) integrate it," he said. "Intel is much more likely to take the lead in throwing or forcing new technologies out there, evangelising them and integrating them into (their) products, then backing away if it turns out people don't want them."
See the Hardware News Section for the latest update on everything from MP3 players and PDAs to supercomputing.
Let the editors know what you think in the Mailroom.
